This module is mainly intended for CGI programming, when a perl script generates a page with client side JavaScript code that needs access to structures created on the server.

It works by creating one line of JavaScript code per datum. Therefore, structures cannot be created anonymously and need to be assigned to variables. However, this format enables dumping large structures.

The module can output code for different versions of JavaScript. It currently supports 1.1, 1.3 and you specify the version on the use line like so:

use Data::JavaScript {JS=>1.3}; # The new default
use Data::JavaScript {JS=>1.1}; # Old (pre module v1.10) format

JavaScript 1.3 contains support for UTF-8 and a native undefined datatype. Earlier versions support neither, and will default to an empty string '' for undefined values. You may define your own default--for either version--at compile time by supplying the default value on the use line:

Previously, the module eval'd any data it received that looked like a number; read: real, hexadecimal, octal, or engineering notations. It now passes all non-decimal values through as strings. You will need to eval on the client or server side if you wish to use other notations as numbers. This is meant to protect people who store ZIP codes with leading 0's.

Unicode support requires perl 5.8 or later. Older perls will gleefully escape the non-printable portions of any UTF-8 they are fed, likely munging it in the process as far as JavaScript is concerned. If this turns out to be a problem and there is sufficient interest it may be possible to hack-in UTF-8 escaping for older perls.